Potential of semi-soft coals as replacement for hard coals in stamp charging blend

摘要

In India the use of appropriate imported coals to supplement the inherent deficiencies of indigenous coals for cokemaking is in vogue. Stamp charging is very efficacious for inferior coking coals and has enabled Tata Steel to produce coke of international quality. It has been found to offer scope for the utilization of less expensive imported semi-soft coals to replace expensive imported hard coals. Extensive tests were carried out to assess the blending potential of semi-soft coals for cokemaking by stamp charging in a 7 kg mini-oven, and a 600 kg pilot oven in the laboratory. This was followed by commercial scale trials. The test results clearly indicated that hard coals can be replaced with 30-35 percent of semi-soft coals in the stamp charging blend at Tata Steel without any compromise of coke strength. Semi-soft coals are now in regular use in all Tata's stamp charged batteries.